To go there, is quite easy: take the underground,
line 5 (south to north) to the last station which is TIANTONGYUAN NORTH
( 2 Yuan = 0.2 € one way). When outside you take the bus 945 for quite a
long trip (20 minutes for 1,5 Yuan one way) ). From the bus stop (lost
in the middle of nowhere!) to the actual museum entry, you can walk
around 10' or take a moto taxi.
Same for the return on the opposite side of the road to pick up the bus.